Lightning arrester



Earn. 22, 1935.

E. A. EVERETT LIGHTNING ARRESTER' Filed Nov. '1, 1930 2 Sheets-Sheet 1 Qall-N Jan. 22, 1935. E. A. EVE RETT 1,988,650

LIGHTNING ARRESTER Filed Nov. 7, 1930 2 Sheets-Sheet 2 Patented Jan. 22,1 935 UNITED. STATES PATENT OFFICE:

LIGHTNING Anaas'raa Edward A. Everett, Long Island City, N. 1!.Application November '1, 1939, Serial No. 494,164 13 Claims. (01.175-30) This invention relates to lightning arresters circuit while ithas comparatively low resistance and has for an object to provide anarrester to the discharge of lightning. Arresters have which is compact,easily assembled, and disasalso been made in which the spark gap andresembled and readily inspected when in service. sistor element are usedin multiple to discharge 5 Another'object'of the invention is to providean lightning. The present invention can be readily 5 arrester which canbe mounted upon a terminal adapted for discharging lightning by thespark block of a commercial type; another object of the gap method,however, a resistant compound has invention is to provide 'a lightningarrester of been found suflicient for this purpose, without the theresistor type which can be connected into one use of spark gaps withtheir liability to become or more circuits to discharge lightning. Otherfused. 10 objects of the invention will appear from the fol- It is"found, in practice, that a resistant has the lowing specification andthe accompanying drawcharacteristic of being able to discharge lightningings, in which, for lightning arrester purposes without material Fig. 1is an elevation, partly. sectioned, of a change in use and with acomparatively large terminal block fitted .with an arrester accordingcapacity. For this reason spark gaps are not 15 to the presentinvention; used in this arrester. The compound referred to.

Fig.2 is a plan view'corresponding to Fig. 1; is more particularlydescribed in my co-pending Fig. 3 is an elevation, partly sectioned,showing application Serial No. 493,097 filed, November 3, aslightmodification'of the arrester construction; 1930, which has matured intopatent Number Fig. -4 is a horizontal cross-section of the 1,939,679. 20mounting for the arrestertaken on the top of the This arrester isconstructed so that it can be connecting strip; readily inspected on theground and so that it 4 Fig. 5 is another modified form'of the invenmaybe takenapart and any of its parts replaced. tion shown insectionalelevation in whicha pluwithout impairing the operation of the device.

rality of resistor elements are provided for dis- The constructionincludes a central stem to which 25 charging lightning'from a pluralityof independone of the connections may be made, as for inent circuits,this figure also shows one applicastance the ground connection. Thelower part tion of the deviceto the circuits of a railway of this stemis'surrounded by a hollow insulating signal system; stem and around thishollow stem a cylinder of '30 Fig. 6 is an endelevation, in section,correthe resistor is placed. The bottom face of the sponding to Fig. 5,and; resistor directly contacts with terminal strips Fig. 7 is. a planview correspon in t 8. 5, leading to the conductors and the top faceconnects by a washer or spring disc with the central Fig. 8 is anothermodification, in sectional elestem. ,This provides a path of very highrevation, in which a pair of discharge elements consistance between theterminal strips and the cen- 35 nect a plurality of independent circuitswith a tral stem which ordinarily does not influence the plurality ofgrounds. normal operation of the circuit, but which on the In theinstallation of railway signal systems, it discharge of lightning lowersits resistance and is common practice to terminate the insulated permitsthe discharge of lightning to ground. As

4,0 conductors which control the apparatus in juncsoon as the lightningis discharged and the re- 40 tion boxes andinstrument cases and thesewires sister has cooled 011?, its high resistance to the are usuallyconnected to terminals whichare normal circuitis restored. The resistoris enmounted on a porcelain base. A standard form closed by a bellshaped glass or transparent conhasbeen adapted for this base, by theAmerican tainer to protect it against the accumulation of '45 RailwayAssociation, which is known as the R. dust and foreign matter and tofacilitate inspec- A S. A. terminal" and the purpose of the presenttion.

invention is to construct a lightning arrester so In the drawings 11 isa terminal block, usually that it may be mounted upon a standard base.made of porc n, pp ti th b d Posts Arresters of this type have beenmade, which in- 12 and 13, to which the electric wires are con- 9 cludea spark gap by the metallic plates across nected and the circuit ismaintained between which the lightning jumps when a brealmlown thesebinding posts by the connector strip 14, voltage is reached. Anotherform of arrester in which for convenience in application is usuallycommon use includes a resistor element, that is, applied with a jawconnection. In the form an element which has the characteristic ofoiiershown in Fig. 1, the arrester is mounted upon ing a comparativelyhigh resistance toth normal the connector, strip 14 by providing anenlarged aperture in the center of this strip, as indicated in Fig. 4through which the stem ,75 projects from the flanged base 71. The base71 and the stem are preferably formed integral from a moulded insulatingmaterial, such as bakelite. The binding post 72 is centered in theprojecting stem 75 and is thoroughly insulated from the connector strip14. This binding post may be provided with a flanged head as at in Fig.3 and embodied in the mould of the stem, or it may be fitted to the stemafter it is moulded by moulding a nut-73 in the flange 71, into whichthe stem is screwed until the collar 76 rests upon the stem 75. The postmay be further secured in the stem by the use of a suitable adhesivecement as indicated at 74.

A cylindrical resistor 77 with a tapered aperture is mounted upon thetapered stem 75 as shown in section in Figs. 1 and 3, a spring washer 78is mounted on the post 72 to engage the upper end of the resistor 77, acollar 79, also mounted on post 72 restsupon the washer 78 and thiscollar is clamped in place by the nut 81' and washer 80 on the stem 72.

In order to protect the resistor against dustand foreign matter and, atthe same time, to

make inspection easy,a transparent cover in the form of thebell shapedglass 84 is mounted upon collar 79 and is clamped in place between thegasket 82 at the top' and gasket 83 at the bottom and by the washer 80and nut 81.

It will be noted that the yielding washer 78 is rigidly engaged by thecollar 79 which is clamped by the washer 80, also that the glass bell 84is engaged by the yielding gaskets 82 and 83 clamped by the washer 80with the purpose of eilecting a tight seal around the glass container84', and, at the same time, securing pressure between washer '78 and theresistor 77. It

will be observed that by removing the binding nuts on the terminal post27 the container 84; washer 78, resistor 77 and stem 75 maybe removedfrom the connector strip 14 thereby facilitating inspection, replacementof parts and assembling.

In the construction shown in Figs. 1, 2,3 and 4 the line circuit isusually connected to the binding posts 12 and 13 and the groundcircuitis connected to the central post at 20-. It is apparent that acircuit is established from the connector strip 14 to the terminal post72 through the mass of the resistor 77 which has its lower faceconnected with the connector strip 14 and its upper face connected withthe post 72 through the washer 78. This will discharge lightning inaccordance with the characteristic of the resistor 77 for this purpose.It should here be noted that the position of the line conductors and theground connection can be reversed without impairing the operation of thedevice as a lightening arrester. 3

Fig. 5 illustrates a'form' of my invention in which a plurality ofresistors are mounted upon a base llb from which stems 75 project foreach "arrester unit. In this construction it will be noted thatthe endbinding post 101 connects to terminal plate 103, flush with the top ofthe mounting and extends in a continuous piece on one side below theresistors of the units 105. 106 and 107; and the other end binding post102, connects to a similarplate 104, flush with the top of the mountingand extending in a continuous piece on the opposite side belowtheresistor elements 105, 106 and 107. As indicated Fig. 6, each of theresistors 77a, rest upon the conductor strips 103 and 104 and form ashunt in multiple between each of these strips.

One application of this arrester is illustrated in Fig. 5 to a railwaysignal system in which advantage is taken of the grounding effects ofthe trackrails as well as an independent ground connection to dischargelightning. The central unit of the arrester 105 is grounded by wire 109.The unit- 106 connects by wire 119 to one rail 118 of the track and thebinding post 107 connects by wire 117 with the other rail 116 of thetrack. The track relay 112 is also connected by wire 113 with the post107 and by wire 114 with the post 106. The line circuit connectsto theend post 102 and the line circuit 111 connects to the post 101. -The'endpost 101 also connects by wire 121 to the relay contact finger 122 andthe end post 102 connects by wire to the same relay contact. This is aform of the invention which has gone into extensive use. It will benoted that lightning on either lines 110 or 111 is shunted from theapparatus by the-resistors in each of the units 105, 106 and 107,bridging the contact strips 103 and 104, also that each of theseresistors provide an independent shunt path to ground.

' Another form of this invention is illustrated in Fig. 8 in whicha'pair of arresterunits are connected to a central ground post. It willbe noted that the contact strip 123, th'roughthe metallic collar 124a,is grounded on wire 109 and that lightning on conductor 111 is shuntedthrough the resistor to the contact strips 123,

connecting to ground, also through strip 124, terminal 1-01, andwire 127to rail 118. Lightning 'on conductor 110 is shunted through the resistorof the arrester to the ground plate 123 andto the plate connected toterminalpost 102 and by wire 126 to the rail 116. The plates 123, 124and 125 are flush with the top of the base 11b and are separate fromeach other, the plates 123 and 124 are bridged by theresistoron stem 107and the plates 123 and 125' are bridgedbythe resistor on stem 106.

This invention permits a variety of applications and is intended tocover a full range of equivalents.

Having thus described my invention, I claim:

1. In a lightning arrester, the combination, a

conducting strip, an insulating stem projecting at right angles thereto,a terminal post centered in said stem, a cylindrical resistorsurrounding said stem and having one end connecting with said strip, aspring washer mounted on'said terminal post engaging the opposite face.of said resistor, a sleeve on said post engaging said washer, atransparent cylindrical container mounted on said terminalipost, agasket on said container and a nut on said post for clamping said strip,resistor, washer and container in place.

2. In a lightning arrester, thev combination, a conducting strip, aflange with an insulating stem, a terminal post centered in said stem,said strip resting upon said flange, a cylindrical resistor mounted onsaid stem and having one end engaging said strip, a washer mountedonsaid post engaging the opposite end of said resistor, a collar on saidpost engaging said .washer, an insulated cylindrical container mountedon said collar and a nut on said post for clamping said strip, resistor,washer, collar and container in place.

3. In a lightning arrester, the combination, a conducting strip, aflange of insulation with a stem, 9. terminal post centered in saidstem, said 1,9ss,eso

strip resting upon said flange, a cylindrical resistor mounted on saidstem and having one end engaging said strip, a spring washer mounted onsaid post engaging the opposite end of said resistor, a collar on saidpost engaging said washer, a cylindrical glasscontainer enclosing.

said resistor, a gasket mounted on said collar engaging said glasscontainer, and a nut on said post clamping said resistor in place andindependently clamping said container through said gasket.

4. In a lightning arrester, the combination, a rectangular insulatingblock, a plurality of arrester elements arranged in a row on said block,each of said elements having a resistor, projections formed integralwith said block engaging said resistors to hold said resistors in placeand a plurality of bars spaced longitudinally and flush with the surfaceof said block, said resistor elements resting upon said bar 5. In alightning arrester, the combination, a rectangular insulating blockhaving spaced projections thereon, a plurality of arrester elements,each placed around one of said projections and having a resistor,parallel conducting bars on said block passing on each side of saidprojections,

' said bars being bridged by said resistors.

6. In a lightning arrester, the combination, a conducting strip havingan aperture, a flange of insulation with an integral stem projectingthrough saidaperture, said strip resting on said flange and projectingbeyond said flange, means for supporting the projecting ends of saidstrip, a terminal post projecting from said stem, a cylindrical resistorcentered on said stem with one face resting on said strip and a bindingnut on said post clamping said resistor, flange and strip in place.

"I. In a lightning arrester, the combination, a conducting strip havingan aperture therein, a flange of insulation with an integral stemprojecting through said aperture, said strip resting on said flange andprojecting beyond said flange,

a terminal post projecting from said stem, a resistor surrounding saidstem with one face resting .on said strip, a spring resting on saidresistor and a binding nut on said terminal post clamping said resistor,strip and flange in place through said spring. a

8. In a lightning arrester, the combination, a conducting strip, aflange of insulating material with 'an integral stem, a terminal postcentered in said stem, said strip resting upon said flange andprojecting on each side beyond said flange, a resistor mounted on saidstem and resting on said strip and means for clamping said resistor,

strip and flange by a nut on said terminal post.

9. In a lightning arrester, the combination, a conducting strip with anaperture therein, a flange of insulating material with a stem projectingthrough said aperture, said strip resting on said flange and projectingon at least one side substantially beyond said flange, a terminal postcentered in said stem, a cylindrical resistor surrounding said stem andhaving one face making electric contact with said strip opposite saidflange, a spring washer mounted on said terminal post and engaging theopposite face of said resistor and a nut on said post for clamping saidwasher, resistor, strip and flange in place.

10. In a lightning arrester, the' combination, a rectangular insulatingblock having a pair of parallel grooves, a terminal post at each end ofsaid block, a conductor strip connected to each post, said stripsembedded in said parallel grooves flush with the top of said block and aplurality of arrester elements arranged on the centre line of saidblock, each of said elements having a resistor bridging said conductingstrips.

11. In a lightning arrester, the combination, a block of insulation, aterminal post at each end of said block, a conducting strip connected toeach post, said strips extending parallel to each other'on said block,said block having projections between said strips and an arresterelement mounted on said projections and resting upon the top of saidstrips. I Y

12. In a lightning arrester, the combination, a block 01' insulation, aterminal post at each end of said block, a conducting strip connected toeach post, said strips extending parallel to each other on said block,said block having integral projections between said strips, an arresterelement surrounding each ot said projections and bridging said stripsand a terminal post centered in each of said projectionsand clampingsaid arrester element in place.

13. In a lightning arrester, the combination, a block of insulation, aterminal post at each end of said block, a conducting strip connected toeach post, said strips extending parallel to each other and embedded insaid block soas to be subjstantially flush with the surface of saidblock,

terminal posts mounted in said block centered between said strips; anindividual arrester element mounted on each post and arranged to bridgesaid strips and forming a lightning discharge path between said postsand strips and an insulating cover for each element secured in place bysaid terminal posts.

EDWARD A. EVERE'I'I.

